This strange little building is easy to miss for it is built into a large boundary wall. Look carefully and you will see that the curves and width are in fact a building. There is a small blocky entrance with a large lintel overhead. The walls are thick and made out of substantial blocks of stone. There are no windows. The roof is domed. It doesn't appear to be corbelled - there are huge slabs of stone laid horizontally then others laid upon them. There may well be small stone infill and then there is an earth topping, now pretty well covered with bracken and heather. Steps take you down into the interior, a low rectangular space, now filled with rubbish. The floor is made of earth. It feels warm, secure and snug. There are signs of blackening on the walls, evidence of smoke. Emerging again you can see the remains of another rectangular enclosure in front. This doesn't seem to have had a roof and I wonder if it was a plunge pool.
I have yet to confirm it but this seems to be a sweat lodge - a sort of Irish sauna. A turf fire was lit and allowed to burn for up to 5 hours until a good heat had been achieved, the entrance being plugged with turf sods. Then the fire was extinguished, the ashes raked aside and damp rushes put on the floor. People entered through the 'creep' ,and remained until hot and sweaty. Red hot Stones could also have been added to maintain the heat. Once you were sufficiently sweaty you then got out and went into the cold plunge pool. This could be repeated several times. This was seen as a cure for rheumatism and arthritis, or just a good way of relaxing after a hard days work in the damp. It seems men and women used sweat lodges, sometimes together.
To bring sufficient turf to what are usually remote areas would have required a lot of effort (two donkey cart loads have been estimated) as would have maintaining the heat. There are some suggestions that the sweat lodges were used for conscience altering experiences as well, combined with healing.
Of course you would have to go in! The entrance is down two steps and then you find yourself within a very low ceilinged rectangular space. Not more than five people could have fitted in here without discomfort. As it is , it would have been quite claustrophobic and intimate. Where there some kind of benches to sit on or did you just hunker down on the rushes? Once the 'creep' had been plugged it would also have been very dark, steamy and pungent from the turf. It seems men and women could use the lodge at the same time, nakedness being acceptable.
Other suggestions for this little building include a cró - a shelter for animals. It would be very difficult to get sheep down into the space, and even harder to get them out again. The horses were intrigued the time I visited, but only because their horse nuts were stored within!